This invention is directed to improvements in a fuel injection valve, and a method for adjusting the valve.
In most of the known fuel injection valves, the fuel is prepared via a tang protruding from the valve, or by a swirling preparation by means of swirl-generating openings. Another kind of fuel preparation is also known, in which the fuel downstream of a sealing seat is directed onto at thin plate (known as a director plate) provided with a plurality of aligned injection ports of a defined length-to-width ratio. Downstream of this plate that performs the fuel quantity metering, there may also be a further injection port. To secure the plate, a preparation sleeve receiving the injection port may be braced against a nozzle body of the fuel injection valve, with the plate disposed in between.
Such a fuel injection valve, which is described in European Patent 201,190, is very expensive to manufacture and individually adjust, because for proper function, the characteristic dimensions of the nozzle body and the plate must be adapted precisely to one another. Eccentricities between these two parts, in particular, have a deleterious effect on the injection pattern attainable. Adapting the fuel quantity, which is dependent on the diameter and length of the injection ports and must be performed individually for each fuel injection valve, is also difficult, because the small dimensions of the plate make it hard to handle.